Question

How many attempts at most will be required to crack a shift cipher?​

Answer 1

Without further information on the hypothesis, it's impossible to make any calculations on how many attempts one would need to succesfully hack a Shift Cipher structure.

Due to its huge success and acceptance lately in our society, with even airplane companies accepting criptocoins, everything related to it has been given a lot of attention.

Therefore, It's gradually becoming harder and harder to get any proof ways to hacking these platforms and system.

You may also consider that, even if we could logically come to a calculation, it'd take a lot more information on the scenario, such as the skills of whoever is trying it, a possible time limit, hardware setup, possible intells and so on.